Hydrogen Sulfide Gas
- Analysis results confirmed the presence of high concentrations of Hydrogen Sulfide Gas each time the SPS 511 operated, with a typical daily peak (before dosing) of between 40 ppm and 50 ppm Hydrogen Sulfide Gas.
- Immediately following the commencement of dosing, the concentration of Hydrogen Sulfide gas was reduced to between 20 ppm and 30 ppm. After 7 weeks of dosing, the level of Hydrogen Sulfide Gas was reduced to between 3 ppm and 8 ppm.
- Since dosing began, peak and average Hydrogen Sulfide Gas concentrations have reduced by half (and continue to fall), as has ORP (refer to results in the following summary).
- Prior to dosing, several odour complaints were registered each day from the school staff.
- Since dosing began, there have been no odour complaints from the school staff, who are quoted as being "ecstatic" about the improvement.
Sewage Pumping Station
Objective: To significantly reduce hydrogen sulfide gas production.
Monitoring was initiated on 8/11/93. The average H2S gas production for the 2 week period
August 11, 1993 to August 24, 1993 was approximately 30 ppm. On August 24, 1993, a program of dosing of BIOSPAN BR90 was commenced at WS12, and is continuing.
H2S gas production has been monitored continuously throughout. An 80% reduction in gas
production has been sustained with an average reduction from 30 ppm to 6 ppm.